The clean-up is continuing in Hungary days after a torrent of toxic sludge from an alumina plant tore through three villages 100 miles west of Budapest.
Hungarian officials have said that pollution levels from the spill had subsided in the Danube and there was no risk of a biological or environmental catastrophe in the river.
But while the spill's impact on the Danube may be limited, western Hungarian villages that bore the brunt of the sludge torrent could suffer in the longer term.
According to environmental group Greenpeace, test samples from the sludge showed that government health and science agencies had underestimated the ecological dangers unleashed
The villages nearest the burst reservoir have turned into a red-stained wasteland, with walls and lamp posts stained red to a height of three meters, fences shattered, trees uprooted, and objects as heavy as cars swept away.
According to Greenpeace, arsenic, mercury and chromium levels were found to be especially high in Kolontar, contrary to earlier claims by the National Academy of Sciences which said the sludge contained no harmful levels of heavy metals.
At least seven people were killed and more than 150 injured in the disaster, mainly as a result of burns and eye ailments from the caustic and corrosive sludge.
All waterlife died in the smaller Marcal River, first struck by the spill. There were also reports of sporadic fish death on Thursday in the Raba and Mosoni-Danube rivers. There were no reports of major damage to the main branch of the Danube.